BASE OF COMPOSITION FOR OXYGEN TREATMENT OF TERRIGENOUS RESERVOIR AND DECLAYING OF BOTTOMHOLE FORMATION ZONE Russian patent published in 2007 - IPC C09K8/74 C09K8/528 

FIELD: oil and gas production.

SUBSTANCE: invention can be employed in well development and operation targeted to intensify oil inflow from formation constituted preferably by terrigenous reservoirs, including those with carbonate inclusions. Base of above-indicated composition contains, wt %: sulfamic acid 4-40, ammonium fluoride or ammonium bifluoride, or ammonium bifluoride-fluoride 4-40, nitric acid-urea reaction product 10-90, phosphonic acid organic derivatives 0.5-10, and corrosion inhibitor 0.5-5. Use of such base prevents formation of sediments, including secondary ones, both at normal and at elevated (above 90°C) formation temperatures; provides dissolution of terrigenous reservoir, including those with carbonate inclusions, resulting in high-degree declaying of formation due to increased degree of dissolution and dispersion of clay material; enables preparation of working fluids from base with fresh and mineralized water; and also prevents formation of stable emulsions and settling of iron-containing sediments into bottomhole zone of formation. Invention in more details is reflected in dependent claims.

EFFECT: improved performance characteristics of composition.

4 cl, 2 tbl